A scanning probe microscope (SPM) is a general term for various new probe microscopes (such as an atomic force microscope AFM, a laser force microscope LFM, a magnetic force microscope MFM, etc.) that are developed on the basis of scanning tunneling microscopes, and is a high-tech product integrating light, machine and electricity by comprehensively using modern scientific and technological achievements such as the optoelectronic technology, the laser technology, the weak signal detection technology, precision mechanical design and processing, the automatic control technology, the digital signal processing technology, the applied optics technology, computer high-speed acquisition and control, and the high-resolution graphics processing technology.
As a microscopic tool, the SPM has clear advantages compared with various previous microscopes and analytical instruments. Firstly, the SPM has a very high resolution and can easily “see” atoms, which is difficult to achieve by general microscopes or even electron microscopes. Secondly, the SPM obtains a real-time, high-resolution image of the real surface of a sample. Unlike some analytical instruments, the surface structure of the sample is estimated by indirect or computational methods. Thirdly, the SPM has no strict requirements for operating environment. It can be used not only in a vacuum, but also in an atmosphere at a low temperature, normal temperature, high temperature, and even in a solution. Therefore, the SPM is suitable for scientific experiments in various working environments.
However, the commercially available scanning heads adopt a design that exposes the signal lines outside the scanning head. Since the scanning head has a very thin signal line with a small solder joint, it is necessary to be very careful when installing and operating the scanning head because the signal line is easy to be tear off and difficult to be maintained.